Hydraulic press for molding and drying stereotype matrices



vApril 1935- i K. SCHAFLEIN 1,996,174

HYDRAULIC PRESS FOR MOLDING AND DRYING STEREOTYPE MATRICES Filed March 31, 1935 IIIIIIIIII III'IIIIII -C 7 y E //f a [21 van for 1522? Jcjacy'lezkz Patented Apr. 2, 1935 UNITED STATES HYDRAULIC PRESS FOR MOLDING AND DRYING STEREOTYPE MATRICES Karl Schaflein, Berne, Switzerland Application March 31, 1933, Serial No. 663,708

In Germany April 15, 1932 L 2 Claims.

The invention relates to a hydraulic press for molding and drying stereotype matrices and hav-' ing a movable press head, the characteristic feature being that the press head is lowered for molding by hydraulic pressure on one end. surface of the piston and is then relieved from the hydraulic pressure, so that the drying of the molded'matrices takes place'in the molding press under the weight of the press head and of the parts connected with same.

In the known hydraulic matrix molding presses the lower press platen is raised by hydraulic pressure against a stationary press head. After the molding the pressure is reduced in order to dry the molded matrices under reduced pressure, but there is nothing to prevent the press platen from sinking further and entirely relieving the pressure.

This drawback is overcome by the invention.

n the drawing one construction of a hydraulic press is shown.

Fig. 1 being a section through the longitudin middle of the press, and

Fig. 2, a cross section.

The press head a is connected by side ties b with the cross piece 0, on which the piston e working in the cylinder dis fastened. The cylinder d is in the press platen ,f. A pump g forces liquid out of the tank h'through pipes i, la into the cylinder d at the top and bottom, from which it flows back through the pipes Z, m, into the tank h.

The control of the valves takes place in the way usual in such presses.

In order to raise the press head when starting to work, liquid is forced by the pump 9 through the pipe is into the annular space below the piston e. After the form together with the matrix and packing has been pushed under the form; the

press head a is lowered by conducting liquid to the upper end of the cylinder through the pipe i.

As soon as the molding has taken place, the pressure can be relieved by leading the liquid away from the upper end of the cylinder d, so that the weight of the press head a, together with the side ties b, and the cross piece 0, will alone act on they matrix during the drying. For drying the matrix the press platens are heated in known manner, for example by electricity or steam.

What I claim and desireto secure by Patent of the United States is: 1

1. In 'a hydraulic press for molding and drying Letters able press head, side ties attached to said press head to guide the latter in the press frame, across piece connecting the lower end of said ties, a piston connected with said cross piece and having two end surfaces, a stationary press platen, a cylinder therein for said piston, means for ap plying hydraulic pressure to one of said surfaces for the purpose of raising said press head, and 7 means for applying hydraulic pressure to the other oneof said surfaces for the purpose of lowering said press head to thereby mold a matrix.

2. In a hydraulic pressfor moldingand drying stereotype matrices, the combination of a movable press head, side ties attachedto said press head to guide the latter in the press frame, a

- cross piece connecting the lower endof said ties,

.a'piston connected with said cross piece and hav- 1 ing two end surfaces, a stationary press platen, a

veylinder'therein for said piston, means for applying hydraulic pressure to one of said surfaces for the purpose of raising said press head, and means for applying hydraulic'pressureto thev otherone of saidsurfaces for the purpose of lowering said press head to thereby mold a matrix,

the hydraulic pressure being released after mold I 10 stereotype matrices, the combination of a mov- 

